With the development of Internet, more and more Internet subscribers are becoming eager to find a convenient method to communicate with each other and get information rapidly whenever and wherever they want. ONLY service is just such a creative service that syncretizes traditional telecommunication and IP technique to meet these requirements. The kernel of ONLY service is distributing an ONLY number for each subscriber, no matter a phone subscriber or a PC subscriber, and whether online or not he is; with help of ONLY number, the ONLY subscribers can be called correctly via his fixed phones (e.g. office telephones and home telephones), mobile phones (e.g. hand phones), pagers and PC personal computers through the ONLY system, which corresponding to the four services such as phone to phone, phone to PC, PC to phone, PC to PC respectively.
ONLY service mainly aims to solve problems in number, charge, mapping of several phone numbers and move of subscribers during communication between PC subscribers and ordinary phone subscribers. In ONLY service, all that a subscriber has to do is to apply for an ONLY number (a virtual number, for example, a special service number 166 and eight figurexxxxxxxxthat includes area code). By using the registered ONLY number, other subscribers can contact the subscriber via devices such as telephone and PC wherever he is. Means through which the ONLY subscriber receives messages is customized by himself, and he can contact calling subscriber real time by ways of telephone and PC, or receive messages with voicemail.
In order to realize ONLY service, an ONLY Server (ONLY Server) and a User Server (US) should be configured. ONLY server is used for call control for all service subscribers; if a subscriber, no matter a PSTN subscriber or a PC subscriber he is, dials ONLY number of the called subscriber, the call will be firstly connected to ONLY Server which then goes on subsequence operations according to the customization made by the subscriber in advance to ensure uniform management for PC subscribers and Phone subscribers; User Server (US) is responsible for strategy control of the calls, which can be customized by subscribers (e.g. rule of call forwarding on busy) and stored in ONLY database. When an ONLY call is coming, ONLY Server will inquire User Server which can obtain call route (number) customized by the subscriber in advance through accessing database, and transferred the call to corresponding communication devices. If the called destination is ordinary PSTN phone or mobile phone, the ONLY Server will then initiate calls to IP phone gateway (GW) where the called number locates; if the destination is PC client, ONLY Server will call the called subscriber directly; and the ONLY server will transfer the call to voicemail of the subscriber in case a message is left.
FIG. 1 illustrates the network architecture and calling process of ONLY service. When calling subscriber calls ONLY number, all of which will be routed to ONLY Server 104 through gateway (GW) 102 or 103; ONLY Server 104 sends requests to User Server (US) 105, and User Server (US) 105 obtains the connection actual phone number or IP address based on the present status of the ONLY subscriber and registry data after searching database 106, then returns to ONLY Server 104; under support of Gatekeeper (GK) 101, ONLY Server 104 initiates calls to actual phone number or IP address via gateway (GW) 102 or 103, Public Switched Telephone Network (PSTN) 109 or 123. User Server (US) 105 returns one or more phone numbers, or IP address customized by the called subscriber in advance to ONLY server 104. Telephones 110, 119, Fax 111, 120, Laptop computers 113, 122 and Modems 112, 121 shown in the drawings are all subscriber devices, and 115 is PC client (PCC).
There is a key technique in ONLY Server, which is when the call stops, ONLY Server need sending a charge request package to User Server to generate charge list. The charge request package should comprise a unique and printable charge ID.
In order to satisfy accessing requirements and implement AAA (Authentication, Authorization and Accounting) functions in traditional IP communication service, the International Standard Organization issued RADIUS (Remote Authentication Dial in User Service) protocols that are RFC2138 and RFC2139 in April 1997, and proposed the updated version of the RADIUS protocol in June 2000, which are RFC2865, RFC2866. In RADIUS protocol, the functions of charge ID are described as follows: charge ID should match the opening records and stopping records of a service in the log easily; at same time, the charge ID should be printable.
Generally, a charge ID is generated based on a call ID. And the call ID, which is comprised by 16 characters that is not always printable, is generated according to the H323 protocol. In current gateway, the charge ID is 16 printable characters that generated through a complex algorithm based on the 16 characters in the call ID. This method is not only very complex but also cannot absolutely ensure uniqueness of the charge ID because of its repeat property during the corresponding process.